David Cameron got a kicking at PMQs today. It was like watching a bully crumble to pieces in the school playground, as his his victim found the strength to fight back. Ed Miliband's device was simple: to sound more Right-wing and more Eurosceptic than the Conservative Prime Minister.

Given Dave's recent wobbly rhetoric, it wasn't so hard to do: he quoted Cameron saying just six weeks ago that a EU treaty renegotiation might allow the British Government to repatriate powers from Brussels, then he delivered the upper-cut: what powers will Cameron repatriate?

Flashman floundered, muttering something about taking the British "bulldog spirit" to Brussels tomorrow. But his tail was firmly between his legs. As Fraser Nelson tweeted: "Cam looks stunned at new attack line. A Eurosceptic Labour would be lethal."

Lethal not just because of the Eurosceptic UK electorate, but because of the men and women sitting, many of them glowering fiercely, behind the PM. Before Cameron had regained his balance, Miliband asked: "Why does the Prime Minister think it is OK to tell his backbenchers one thing and European leaders another?" This – a reference to Cameron's op-ed in the Times – was the most effective line of the day. If Ed Miliband can tease out a Tory rebellion, he'll leave David Cameron looking neutered.

And here's the news that could ruin the PM's week: Owen Paterson, the Secretary of State for Northern Ireland, has apparently told the Spectator that an EU referendum is "inevitable". If Iain Duncan Smith backs Paterson, Cameron could face a mutiny from around his own Cabinet table. It'll be the Tory answer to Operation Valkyrie.